South Dakota voters chose three electors to represent them in the Electoral College via a popular vote pitting incumbent Democratic President Barack Obama and his running mate, Vice President Joe Biden, against Republican challenger and former Massachusetts Governor Mitt Romney and his running mate, Congressman Paul Ryan.

South Dakota has not voted for a Democratic presidential nominee since Lyndon B. Johnson carried it in his 44-state landslide in 1964.

According to a 2012 Gallup poll, South Dakota is the 9th most conservative state in the country, with Republicans having an 11 percentage point advantage over Democrats in terms of party affiliation or identification.

Romney was able to win back southeast Dakota: Obama became competitive there in 2008, when he won Minnehaha County (and many of its suburbs), home to the state's largest city of Sioux Falls, by only 587 votes.

The counties of Buffalo; Dewey; and Todd, where the Crow Creek; Cheyenne River and Standing Rock; and Rosebud reservations are located, respectively, also delivered great margins to the president.